1. Field of the Invention
The present invention relates to a battery module, and more particularly to a battery module that is constructed by incorporating a plurality of cells in a single battery case.
2. Description of Related Art
FIG. 11 shows a conventional battery module 41 composed of a combination of a plurality of cells. In this construction, a plurality of cells 42 are juxtaposed, with a spacing secured in between for a cooling purpose. A pair of battery fixing plates 43 and 44 are disposed at the opposite ends of the array of the plurality of cells 42 in such a way as to have sandwiched therebetween the cells 42. The reference numeral 45 denotes a coupling rod for joining together the pair of battery fixing plates 43 and 44.
Moreover, Japanese Patent Laid-Open Publication Nos. Hei. 9-266016 and Hei. 11-176487 each disclose a battery module constructed by placing a plurality of cells in a battery case, wherein a cooling medium passage or a Peltier element is disposed in the battery case to control the temperature of the battery.
However, any of the above-described conventional battery modules has proved to pose problems as follows. Each of the incorporated cells is separately housed, together with an electrolyte and an electrode plate group acting as a power-generating element, in a cell case. That is, the cells are designed to be usable singly. Such cells are juxtaposed with a spacing secured in between for a cooling purpose, and the array of the cells is sandwiched between the fixing plates or housed in a battery case. The battery module constructed in this way inevitably has an unduly large volume. What is worse, to hold a plurality of independent cells securely, an extra component such as a fixing plate or a battery case is required, and thus the number of assembly man-hours is increased. This results in an undesirable increase in the cost.